[R] how to replace some objects?

[Jacques VESLOT]

you can use as.numeric(factor( )); in your example:
 > ex <- sample(letters[1:3], 10, T)
 > ex
  [1] "b" "b" "c" "b" "a" "a" "b" "b" "a" "a"

 > as.numeric(factor(ex))
  [1] 2 2 3 2 1 1 2 2 1 1

if the order is different, use levels:

 > as.numeric(factor(ex, levels=letters[3:1]))
  [1] 2 2 1 2 3 3 2 2 3 3

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Jacques VESLOT

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Zhang Jian a écrit :
> I want to replace some objects in one row or column.For example,
> One colume: a,b,a,c,b,b,a,a,c.
> I want to replace "a" with "1", "b" with "2", and "c" with "3".
> Like this: 1,2,1,3,2,2,1,1,3.
> 
> How to do it? I donot know how to do it. Thanks.
> 
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> 
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